Left Section:   Bamboo Didgeridoo or Yidaki – Building – Experimental – Easy to build and reliable to play
Right Section: Didgeridoo “From Down Under the mystical Sound”: Some poem trials, some rhymes on the didgeridoo.
(me playing (see Insta @ResEngMike: quite below my contributions), but better go to the famous guys noted below…

Further Reading / References: 
English
Pages/Books: Key Studies by Fletcher, Hollenberg, Tarnopolsky et al.:
from Australian Universities from Sidney, Canberra and Melbourne. You will find the paper references on page: http://newt.phys.unsw.edu.au/jw/didjeridu.html 
focus: Experiment, Theory and Playing.

Book:
David Lindner “The Didgeridoo Phenomenon: 
From Ancient Times to the modern Age – History – Development – Trade Ecology – 

Building Instructions: a German Page: Didgeridoo Planen und Bauen:
https://www.didgeridoo-physik.de/cadsd/cadsd-method/
Access on formulas for tubes and cones (CADSD – Computer Aided Didgeridoo Sound Design”)
David Lindner “Traumzeit – Das Geheimnis des Didgeridoo”,
“Didgeridoo-Phänomen: Von der Urzeit zur Moderne: Didgeridoobau”

Some YouTube “My(!) Favorites” based on my Didgeridoo experiences:
Breathwood (++), Wet Didgeridoo, DidgeridooBreath (+), Didgeridoo Dojo(+), Dubravko Lapaine Didgeridoo(+); Hernan
Liuvolsi (SP), Mack Yidhaky(SP), Didgehouse(D+), James Donaldson Jr. (Didgemonster (+)) and Spirit Gallery.
Yothu Yindi (AUS) and Midnight Oil (AUS)
Players/Teachers:
Djalu Gurruwiwi (AUS), Mark Atkins (AUS), Charlie McMahon (AUS), Xavier Rudd (AUS), Ash Dargan (AUS),
William Barton (AUS), Rolf Harris (AUS), David Blanasi (AUS) and Mitchell Cullen (Didge&Guitar, AUS). 
Stephen Kent (US), Dubravoko Lapaine (RUS), Gauthier Aubé (F), Adèle & Zalem (F), David Hudson (AUS),
Tyler Spencer, Ganga Giri and Dan Flynn … just to mention some famous players…